diff --git a/build/dependencies.props b/build/dependencies.props
index 89f812caa6..649af28432 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -3,12 +3,12 @@
     <MSBuildAllProjects>$(MSBuildAllProjects);$(MSBuildThisFileFullPath)</MSBuildAllProjects>
   </PropertyGroup>
   <PropertyGroup Label="Package Versions">
-    <InternalAspNetCoreSdkPackageVersion>2.1.0-preview3-17018</InternalAspNetCoreSdkPackageVersion>
-    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-preview3-32233</MicrosoftAspNetCoreTestingPackageVersion>
-    <MicrosoftCSharpPackageVersion>4.5.0-preview3-26413-02</MicrosoftCSharpPackageVersion>
-    <MicrosoftExtensionsClosedGenericMatcherSourcesPackageVersion>2.1.0-preview3-32233</MicrosoftExtensionsClosedGenericMatcherSourcesPackageVersion>
+    <InternalAspNetCoreSdkPackageVersion>2.1.0-rc1-15774</InternalAspNetCoreSdkPackageVersion>
+    <MicrosoftAspNetCoreTestingPackageVersion>2.1.0-rc1-30613</MicrosoftAspNetCoreTestingPackageVersion>
+    <MicrosoftCSharpPackageVersion>4.5.0-rc1-26419-03</MicrosoftCSharpPackageVersion>
+    <MicrosoftExtensionsClosedGenericMatcherSourcesPackageVersion>2.1.0-rc1-30613</MicrosoftExtensionsClosedGenericMatcherSourcesPackageVersion>
     <MicrosoftNETCoreApp20PackageVersion>2.0.0</MicrosoftNETCoreApp20PackageVersion>
-    <MicrosoftNETCoreApp21PackageVersion>2.1.0-preview3-26413-05</MicrosoftNETCoreApp21PackageVersion>
+    <MicrosoftNETCoreApp21PackageVersion>2.1.0-rc1-26419-02</MicrosoftNETCoreApp21PackageVersion>
     <MicrosoftNETTestSdkPackageVersion>15.6.1</MicrosoftNETTestSdkPackageVersion>
     <MoqPackageVersion>4.7.49</MoqPackageVersion>
     <NETStandardLibrary20PackageVersion>2.0.1</NETStandardLibrary20PackageVersion>
diff --git a/korebuild-lock.txt b/korebuild-lock.txt
index b419d767b9..9d4ef8c888 100644
--- a/korebuild-lock.txt
+++ b/korebuild-lock.txt
@@ -1,2 +1,2 @@
-version:2.1.0-preview3-17018
-commithash:af264ca131f212b5ba8aafbc5110fc0fc510a2be
+version:2.1.0-rc1-15774
+commithash:ed5ca9de3c652347dbb0158a9a65eff3471d2114